Ladder extension



FIG. 1 is a front elevation view of a ladder extension showing my new design;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a right side elevation view thereof, the opposite side being a mirror image of the shown;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is an isometric view thereof.

The broken lines shown in FIG. 6 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a ladder extension, as shown and described. 